Screening for breast cancer is not effective unless the appropriate diagnostic tests are used to definitively diagnose any potential cancer. Although guidelines have been developed to maximize diagnostic accuracy, in a preliminary study we found that 14 percent of low-income Iowa women with abnormal screening results had diagnostic follow-up that was inadequate based on these guidelines. Studies about the quality of breast cancer care have typically included only patient factors and have ignored the fact that communities in which women reside may also shape health status. Community deprivation is independently associated with breast cancer incidence and survival and with behaviors, but it is unclear if low-income women from areas with higher social and economic deprivation are less likely to receive adequate diagnostic follow-up and what the potential reasons are for such disparities. The goal of the proposed project is to analyze existing data of 2,800 low-income Missouri women with abnormal breast cancer screening results and to collect primary data of nearly 300 low-income Missouri women in order to test four different pathways by which low-income women from areas with higher deprivation are less likely to receive adequate diagnostic follow-up in a future R01 project. The four pathways are: I) under investment in community infrastructure, including health care; II) disruption of the social fabric/cohesion; III) individual characteristics of women who reside in these areas are key rather than the characteristics of the areas in which they live; and IV) deprivation directly influences adequacy of diagnostic follow-up. In the proposed study we will be able to partly test pathways I, III, and IV in a multilevel conceptual model, although not all variables for these pathways will be available in the existing data sources. Data collection instruments will be tested and potential biases in recruitment and participation will be assessed in a developmental study. These primary data will form the basis for pathway II (social cohesion), which will be tested simultaneously with the other three pathways in a future R01 grant to examine reasons why women from areas with higher social and economic deprivation are less likely to receive adequate diagnostic follow-up.